Role Of Atp In Muscle Contraction

Then, turn back to your text and read the rest of 8.3 (energy sources for contraction) and 8.4 muscular responses. Answer the following:

Discuss the specific roles of ATP in generating a muscle response to a nerve signal.
ATP provides the energy necessary for contraction. However the muscle fibers only contain enough ATP for a short period of contraction. When new ATP arrives it allows the myosin and actin to release with stored energy for the next movement. In the HEAD the ATP is hydrolyzed which re-cocks the lever arm. This newly released energy from the hydrolization is stored in ADP+Pi. This done by creatine phosphate. It is several times more abundant then ATP is the muscle fibers. Creatine phosphate stores energy in the mitochondria. When the ATP supply is sufficient an enzyme catalyzes the synthesis of of creatine phosphate which stores excess energy in its phosphate bonds. As the ATP decomposes the creatine phosphate energy transfers to ADP molecules which become ATP. However there is a finite supply of this and once exhausted energy is taken from glucose by cellular respiration to synthesize ATP.

Discuss the specific roles of calcium in generating useful muscle contractions. Calcium diffuse into the muscle fiber’s sacroplasm through T-Tubules previously opened by the Na+ or Sodium. In the presence of a high concentration of calcium the troponin and tropomyosin interact in some way and calcium ends up bound in some way to the troposin and the tropomyson is pulled aside exposing the binding sites for the myosin